Potassium chloride supplementation reduces blood pressure in salt sensitive hypertensive minority populations and we believe this effect is mediated through both natriuresis and reduction of systemic vascular resistance. The aims are: to identify ss hispanic and Afro-American hypertensive and borderline hypertensive individuals to demonstrate the effects of short and long term oral potassium chloride supplementation on blood pressure in these ss patients, to determine if potassium chloride- induced changes in blood pressure are associated with natriuresis, to determine if potassium chloride-induced changes in blood pressure are due to a decrease in systemic vascular resistance, to determine if short and long-term potassium chloride supplementation improves local sympathetic spill over rates and to determine if short and long term potassium chloride supplementation improves endothelial dependent and/or endothelial-independent vasodilation in ss individuals.